CN111724760A

CN111724760A - Apparatus, system and method for audio signal processing

Info

Publication number: CN111724760A
Application number: CN202010201900.8A
Authority: CN
Inventors: A.福尔默; M.布罗德森; J.雷尔曼
Original assignee: Draeger Safety AG and Co KGaA
Current assignee: Draeger Safety AG and Co KGaA
Priority date: 2019-03-21
Filing date: 2020-03-20
Publication date: 2020-09-29
Anticipated expiration: 2040-03-20
Also published as: CN111724760B; DE102019001966B4; US20200302909A1; US11107454B2; DE102019001966A1

Abstract

The invention relates to an apparatus for noise dependent audio signal processing having a correction microphone, a reference microphone, a classification unit, an active noise reduction (ANC) unit and a first loudspeaker. The correction microphone is arranged in the immediate vicinity of the region of the ear provided for the wearer of the device and is configured to: the sound signal in the area is recorded and forwarded as a correction signal. The reference microphone is arranged and constructed such that: ambient noise in the ambient environment from the wearer of the device is recorded and forwarded as a reference signal. The classification unit is configured to: a reference signal is received and divided into at least one first class and a second class of signal components according to its frequency spectrum and its amplitude and a classified signal is output. The ANC unit is configured to: receiving a correction signal; processing the correction signal based on the classified signal; and outputs a corresponding audio signal. The first speaker is configured to: receiving an audio signal and providing a corresponding sound signal output.

Description

Apparatus, system and method for audio signal processing

Technical Field

The invention relates to a device for noise-dependent audio signal processing and a system for noise-dependent audio signal processing having the device for noise-dependent audio signal processing. The invention also relates to a method for noise dependent audio signal processing.

Background

Communication of rescue personnel is of vital importance in the field of disaster relief, especially in the work of firefighters. However, the area where such rescue is performed is often very noisy, for example due to a siren, ambient noise of the vehicle or ventilation system. Through this, communication required for the rescuer becomes very difficult.

It is known that: especially in the fire fighting field, voice communication is ensured by additional electrical communication equipment, such as headphones or headphones. In this case, the electrical communication device may be configured to: signals are received from a microphone and processed in relation to noise such that speech components within the signals are enhanced and noise components are attenuated.

Disclosure of Invention

The task of the invention is that: an improved audio signal processing is provided for persons exposed to a noise environment, in particular for firefighters during rescues.

According to the present invention, to solve the task, according to a first aspect of the present invention, a device for noise dependent audio signal processing is proposed, the device having a correction microphone, a reference microphone, a classification unit, an Active Noise Cancellation (ANC) unit and a first speaker.

The correction microphone is arranged in the immediate vicinity of the region of the ear provided for the wearer of the device and is configured to: the sound signals in the area set for the ear are recorded and forwarded as correction signals.

The reference microphone is arranged and constructed such that: ambient environmental noise in the ambient environment from the wearer of the device is recorded and forwarded as a reference signal. The correction microphone and the reference microphone are configured as two different microphones which, according to the invention, are oriented differently, wherein the correction microphone is oriented towards the region provided for the ear of the wearer of the device and the reference microphone is oriented away from the wearer of the device towards the surroundings of the wearer of the device.

The classification unit is configured to: a reference signal is received and divided into at least one first and second class of signal components according to its frequency spectrum and its amplitude and a classified signal is output.

The ANC unit is configured to: receiving a correction signal; processing the correction signal based on the classified signal; and outputs a corresponding audio signal.

The first speaker is configured to: receiving an audio signal and providing a corresponding sound signal output.

The invention is based on the recognition that: the pure processing of an electronically transmitted communication signal, as used in known communication systems, is not helpful in situations in which loud noises are sounded immediately beside the rescuer. Furthermore, within the scope of the present invention, it has been recognized that: pure hearing protection may prevent rescuers from perceiving important sound signals in their surroundings, such as the voice of people standing around, vehicle noise, or fire noise. Based on this recognition, the invention solves the proposed task by a combination of noise classification and subsequent classification-related processing by the ANC unit.

In this way, signals that are important for the rescuer can advantageously be classified such that they do not change, are not enhanced or at least only weakly attenuated. While pure interference noise can be safely suppressed or at least strongly attenuated by active noise reduction by means of the ANC unit. Hereby, signals important for the rescuer can be perceived, while still ensuring a certain degree of hearing protection.

It is also advantageous in terms of the device according to the invention that it can be easily integrated into existing communication devices. In this way, the signal processing can be carried out with suitable adaptation by the existing communication device, so that a simply implementable use of the reference microphone or reference microphones only has to be implemented in such an existing device.

The device according to the invention also advantageously allows different applications, since different classes, in particular different kinds of classes, are conceivable. Furthermore, different arrangements of the ANC unit can also be realized according to the invention. Thus, a personalized use of the device according to the invention is also possible.

Another advantage according to the invention is that: by processing the correction signal by means of the ANC unit, the general noise load of the wearer of the device according to the invention can be significantly reduced. Thus, one of these categories may comprise the noise to be attenuated, which is strongly attenuated by the active noise reduction in the range of the sound signal output and perceived by the wearer of the device according to the invention.

The division into a classification unit and an ANC unit as distinct electrical components within the device according to the invention may also be implemented as a functional division within a single processor, in particular within a single electrical component.

The classification by the classification unit is based on a method for pattern recognition that analyzes the spectrum and amplitude of the received reference signal. In principle, methods for pattern recognition suitable for this are known from other technical fields, such as the application of neuronal networks or support vector machines or codebooks. As mentioned in the introduction, specific implementations of such a method for pattern recognition are known in the field of sound signal processing, so that a detailed description of the method is omitted below.

The classified signal comprises an unambiguous assignment of the signal component of the reference signal to the at least one first class and second class. Thus, the ANC unit can process the corresponding signal components differently according to the assigned categories.

Here, the classified signal may be a unique signal that includes a reference signal together with current information about which class of signal components is currently present. However, the classified signals may also be formed by a combination of signals. The classified signal may comprise, in particular, a reference signal and at the same time an assignment signal which is synchronized in time with the reference signal and has an assignment to the class which is present for the current signal component.

In principle, the operating principle of the ANC unit is known with regard to active noise reduction of all ambient noise, so that this is not discussed in detail below.

The sound signal in the region provided for the ear usually also at least partially comprises ambient noise. Preferably, these ambient noises do not comprise, or at least do not substantially comprise, the part of the sound signal output by the first loudspeaker.

Within the scope of the invention, all acoustic phenomena in the surroundings, i.e. in particular also different kinds of sound signals or noise, from the user of the device are understood as ambient noise. In general, acoustic phenomena in a broad band are referred to as noise, while sound signals generally represent tonal acoustic phenomena having at least one defined spectral range. However, such differences following the protocols of the technical field are not to be understood in a limiting sense within the scope of the present invention. Acoustic phenomena, which are typically noise, may also be referred to as signals or sound signals in the following, and vice versa.

Preferred embodiments of the device according to the invention are described subsequently.

In a particularly advantageous embodiment of the device according to the invention, the device further has a signal enhancer which is designed to enhance the correction signal, the reference signal and/or the audio signal. Advantageously, the signal enhancer, which is designed to enhance the correction signal, enables a particularly precise classification of the signal components of the reference signal by the classification unit. Advantageously, a signal enhancer designed to enhance audio signals enables targeted enhancement of important signal components, i.e. those signal components which are to be output to the user of the device in a well-audible manner in the region of the sound signal output. The signal booster forms a functional component of the device, which can also be embodied in a common electronic component with the ANC unit and/or the classifying unit.

In a further advantageous embodiment, the classification unit is configured to output the reference signal with more than two classes of signal components. Advantageously, the plurality of classes enables a targeted control of the signal component output of the individual signals and/or noise groups within the sound signal output. Thus, the voice component or the vehicle noise within the reference signal may be differently processed from the siren signal or the fire noise. The use of a plurality of categories also enables a particularly personalized use of the device according to the invention for different user groups.

In a preferred embodiment, these categories include at least one of the following sets of signals and/or noise: siren signals, vehicle noise, voice signals, pump noise, ventilation noise, fire noise. A signal and/or noise group within the scope of this embodiment is particularly advantageous for use within the scope of the work of firefighters. In a particularly advantageous variant of this embodiment, the classification unit is also configured to output the reference signal in more than two classes of signal components. In this preferred variant, the noise to be assigned to different signals and/or noise groups can be treated particularly advantageously differently. Thus, siren noise can be strongly attenuated and a voice signal can be output with enhancement. As well as fire noise, pump noise and ventilation noise often form disturbing noise in the operation of the fire fighters, so that strong attenuation of the disturbing noise in the region of active noise reduction of the disturbing noise by the ANC unit leads to a significant reduction of the general noise load in rescue and improves the communication by targeted enhancement of the speech.

In a particularly preferred embodiment, the ANC unit is configured to: the audio signal is determined based on the classified signals such that a sound signal output based on the audio signal is adapted to destructively interfere with a portion of the ambient noise corresponding to signal components from the at least one class of reference signal. Within the scope of this embodiment, the ANC unit is capable of achieving a particularly effective noise reduction.

In a further embodiment of the device according to the invention, the ANC unit is further configured to: receiving a reference signal and a correction signal; processing the reference signal and the correction signal based on the classified signals; and outputs a corresponding audio signal. In this way, the ANC unit advantageously provides a particularly large amount of signal information about the current ambient noise in order to provide an audio signal correspondingly suitable for active noise reduction by means of the first loudspeaker. In principle, for all the embodiments described below, the following variant is advantageous, in which the ANC unit is also configured: receiving a reference signal and a correction signal; processing the reference signal and the correction signal based on the classified signals; and outputs a corresponding audio signal.

In a further advantageous embodiment, the ANC unit is configured to: assigning corresponding sets of signals and/or noise to the classes of classified signals; and processing a correction signal, in particular a correction signal and a reference signal, based on the signal components of the classified signals assigned to the at least one predefined signal and/or noise group, such that the sound signal output based on the audio signal is adapted to interfere with a portion of the ambient environmental noise such that the ambient environmental noise of the at least one predefined signal and/or noise group is perceived with a predefined amplitude in a region of the ear provided for the wearer of the device, said portion corresponding to the signal components of the reference signal from the at least one predefined signal and/or noise group. In this way, a predefined amplitude can advantageously be specified for a predefined signal and/or noise group. In this way, the speech components within the reference signal can be boosted to a predefined amplitude independently of the initial amplitudes of these speech components, whereas the siren signal is not completely suppressed for safety reasons, but is merely attenuated to a very slight predefined amplitude. The use of different predefined amplitudes for sounds from different predefined signals and/or noise groups may advantageously correspond to a prioritization of the determined signal components by a user of the device according to the invention. In this case, particularly important signal components are enhanced, while interfering ambient noise is actively suppressed by processing by means of the ANC unit.

In a further embodiment of the device according to the invention, the device also has a second loudspeaker and an additional correction microphone, wherein the second loudspeaker is designed to: an audio signal or an additional audio signal is received and a corresponding additional sound signal output is provided. Within the scope of this embodiment, the additional correction microphone is arranged in the immediate vicinity of the region provided for the other ear of the wearer of the device and is configured: the sound signals in the area set for the other ear are recorded and forwarded as additional correction signals. Within the scope of this embodiment, the ANC unit is further configured to: additional correction signals are received and the correction signals and the additional correction signals are processed based on the classified signals. In this embodiment, preferably, the ANC unit outputs the audio signal and the additional audio signal. In this way, the directional dependence of the ambient noise can be taken into account in the range of the sound signals output by the two loudspeakers. Within the scope of this embodiment, the ear and the other ear are to be understood as the left and right ear of the wearer of the device. The audio signal delivered to the second speaker may be different from the audio signal delivered to the first speaker. In this embodiment, an advantageous sound signal output according to the invention can be realized particularly advantageously for both ears of the wearer of the device. In particular, within the scope of this embodiment, by using two loudspeakers and two correction microphones, it is possible to achieve particularly effective use of the device according to the invention within the scope of hearing protection.

In a further particularly preferred embodiment, the device has at least one additional reference microphone which is arranged and constructed such that: ambient noise in the ambient environment from the wearer of the device is recorded and forwarded as an additional reference signal. Within the scope of this embodiment, the classification unit is configured to: outputting a classified signal based on the reference signal and the additional reference signal. The use of a plurality of reference microphones within the scope of this embodiment enables a particularly precise detection of the ambient noise and thus a particularly efficient noise reduction within the scope of the sound signal output. Preferably, the use of a plurality of reference microphones enables direction-dependent recording and processing of ambient noise. In a particularly preferred variant of this embodiment, the device has more than two reference microphones. In a further variant of this embodiment, the relative position of the reference microphone and the additional reference microphone, or the relative positions of a plurality of reference microphones, is predetermined. The processing of the signals by the classification unit and/or the ANC unit may be based on such a predetermined relative position between the reference microphones.

In an embodiment of the device, a pre-processing unit is arranged between the correction microphone and the classification unit. The pretreatment unit is configured, for example, as: the correction signal is enhanced. The pretreatment unit is also configured, for example: signal components outside a predetermined spectral range are filtered out.

In a further embodiment of the device, a residual processing unit is arranged between the ANC unit and the first loudspeaker. The residual processing unit is configured, for example, as: the audio signal is at least partially enhanced and the enhanced audio signal is output to the first speaker. In one embodiment, the residual processing unit is further configured to: signal components outside a predetermined spectral range are filtered out.

In a preferred embodiment, the ANC unit is further configured to: an audio signal and an additional audio signal are provided. In this way, for example, a further audio signal can optionally be provided to the second loudspeaker, wherein advantageously the position of the second loudspeaker relative to the first loudspeaker can be taken into account. This may be advantageous, for example, for a device according to the invention which allows, for example, optionally allows the connection of a second loudspeaker.

In a further embodiment, the device also has a microphone holder which fixedly connects the correction microphone and the first loudspeaker to one another in such a way that the relative position of the correction microphone and the first loudspeaker to one another cannot be changed. In this embodiment, it is advantageously ensured that: the correction microphone always receives approximately the same portion of the sound output of the audio signal, which is predefined by its directional characteristic and the directional characteristic of the first loudspeaker, and processes it further according to the invention. The microphone holder can thus advantageously achieve the same quality of signal processing by the device, even in the case of movements of the device or strong physical loads on the device.

In an embodiment of the device according to the invention, the device according to at least one of the above-described embodiments is integrated in a headset. Preferably, in this case, one ear is passively protected against noise, while a correction microphone is arranged according to the invention on the other ear.

To solve the task according to the invention, according to a second aspect of the invention, a system for noise dependent audio signal processing is proposed, the system comprising: an apparatus according to at least one of the above embodiments; and a gas mask and/or helmet, wherein the first speaker is arranged such that the sound signal output is made in an area of an ear provided for a wearer of the gas mask and/or helmet, and wherein the correction microphone is arranged immediately adjacent to the area provided for the ear.

The system according to the second aspect of the invention combines the advantages of the audio signal processing according to the first aspect of the invention with the general advantages of gas masks and/or helmets, for example in the context of the work of firefighters. Within the scope of the system according to the invention, the device according to the first aspect of the invention is particularly advantageous, since helmets and gas masks mostly make acoustic conditions difficult and make the application of conventional hearing protection difficult.

The use of the system within a gas mask advantageously enables: the device according to the invention is particularly simple to integrate in a communication device provided for a gas mask.

According to a second aspect of the invention, the first speaker may be arranged in close proximity to an area provided for the ear of the wearer. This can be achieved, for example, by being arranged in the strapping of the helmet, in particular in the fabric of the strapping of the helmet. This can also be achieved by being arranged on the inner side of the helmet facing the wearer of the helmet. Preferably, by arranging the first speaker, a certain variability of the ear position within the helmet can be achieved, and thus allow the use according to the invention of the system by different wearers having different head styles. In an alternative or supplementary variant, the first loudspeaker is arranged remote from the ear of the wearer of the helmet and/or respirator and on the resonant channel, so that the sound signal output reaches the ear of the wearer of the device according to the invention via the resonant channel.

In a particularly advantageous embodiment of the system according to the invention, the reference microphone is arranged on an outer surface of the gas mask or helmet facing away from the gas mask and/or a wearer of the helmet. Via this, all ambient noise can advantageously be recorded by the reference microphone. In a particularly preferred variant of this embodiment, at least one additional reference microphone is arranged on the outer surface of the respirator or helmet. This enables a direction-dependent processing of the respective reference signal by the classification unit and/or the ANC unit. In one advantageous example of this variant, the plurality of reference microphones are arranged at a fixed predetermined distance from one another. For example, the plurality of reference microphones are arranged in a helmet strap, which may be arranged on a common helmet at the lower edge of the helmet.

In one embodiment of the system according to the invention, the classification unit and/or the ANC unit is arranged inside the helmet in the immediate vicinity of the area of the back scoop of the wearer provided for the system. The system according to the invention can thereby be provided particularly compactly on a helmet.

According to a third aspect of the invention, the object is achieved by a method for noise-dependent audio signal processing, having the steps of:

-recording the sound signal in the region of the ear of the user arranged for the method and forwarding the corresponding correction signal;

-recording ambient noise of a user of the method and forwarding a corresponding reference signal;

-receiving the reference signal, dividing the reference signal into at least one first and second class of signal components according to its frequency spectrum and its amplitude and outputting corresponding classified signals;

-receiving a correction signal, processing the correction signal based on the classified signal by a provided ANC unit and outputting a corresponding audio signal; and also

-receiving the audio signal and providing a corresponding sound signal output.

The method according to the invention has the same method steps as are carried out within the device according to the invention. Thus, the method has the same advantages as the apparatus according to the invention.

The division of the reference signal into at least two classes may be achieved by an actual change to the reference signal, e.g. by an addition of class information. However, the division can alternatively or additionally also be realized by providing an assignment signal which is synchronized in time with the reference signal, wherein the assignment signal indicates the class assigned to the signal component currently present in the reference signal.

In one embodiment of the method according to the invention, the method further comprises: the correction signal, the reference signal and/or the audio signal are enhanced.

In another embodiment according to the invention, the reference signals are divided into more than two categories.

In one embodiment of the invention, the method comprises: assigning a predefined set of signals and/or noise to the corresponding class of classified signals; and processing, by the ANC unit, the correction signal based on the signal components of the classified signal assigned to the at least one predefined signal and/or noise group such that the sound signal output based on the audio signal is adapted to interfere with a portion of the ambient environmental noise such that the ambient environmental noise of the at least one predefined signal and/or noise group is perceptible with a predefined amplitude in a region of the ear of a user arranged for the method, said portion corresponding to the signal components of the reference signal from the at least one predefined signal and/or noise group.

In a further embodiment of the invention, the method further has the following steps:

-recording the further sound signal in the area of the other ear of the user arranged for the method and forwarding the corresponding additional correction signal;

-receiving an additional correction signal and processing the correction signal and the additional correction signal based on the classified signals; and also

-receiving the audio signal and providing an additional sound signal output at the other ear of the user of the method.

-recording other ambient noise of the user of the method and forwarding the corresponding additional reference signal; and also

-outputting a classified signal based on the reference signal and the additional reference signal.

Drawings

The invention should now be further elucidated on the basis of an advantageous embodiment which is schematically shown in the drawing. In detail in these drawings:

fig. 1 shows a schematic configuration of an apparatus according to a first embodiment of a first aspect of the present invention;

fig. 2 shows a schematic configuration of an apparatus according to a second embodiment of the first aspect of the present invention;

fig. 3 shows a schematic configuration of an apparatus according to a third embodiment of the first aspect of the present invention;

FIG. 4 shows a perspective view of the system according to the first embodiment of the second aspect of the invention;

FIG. 5 shows a perspective view of a system according to a second embodiment of the second aspect of the invention;

FIG. 6 shows a perspective view of a system according to a third embodiment of the second aspect of the invention;

FIG. 7 shows a perspective view of a system according to a fourth embodiment of the second aspect of the invention;

fig. 8 shows a block diagram of a method according to an embodiment of the third aspect of the invention.

Detailed Description

Fig. 1 shows a schematic configuration of an apparatus 100 according to a first embodiment of the first aspect of the present invention.

The apparatus 100 for noise-related audio signal processing comprises a correction microphone 110, a reference microphone 120, a classification unit 130, an ANC unit 140 and a first loudspeaker 150.

The correction microphone 110 is arranged in close proximity to a region 114 of the ear provided for the wearer of the device. The correction microphone is configured to: the sound signals in the region 114 provided for the ear are recorded and forwarded as correction signals 118. Here, the correction microphone 110 is oriented towards the region 114 provided for the ear.

The reference microphone 120 is arranged and constructed such that: ambient environmental noise 124 in the ambient environment from the wearer of the device 100 is recorded and forwarded as reference signal 128. Here, the reference microphone is oriented towards the surroundings of the wearer of the device 100. In this case, it is preferable that the directions in which the correction microphone 110 and the reference microphone 120 are respectively oriented are different.

The classification unit 130 is configured to: receives the reference signal 120 and divides the reference signal 120 into at least one first class and a second class of signal components according to its frequency spectrum and its amplitude and outputs a classified signal 134. In this embodiment, the division into the first and second categories is based on signal processing of the reference signal 120 by a support vector machine applied to the spectrum and amplitude of the reference signal 120. Alternatively or additionally, in a further embodiment, not shown, a further known method for pattern recognition is used, for example a method based on a neural network and/or a codebook.

ANC unit 140 is configured to: the correction signal 118 is received, processed based on the classified signal 134 and output as an audio signal 144.

The first speaker 150 is configured to: receives the audio signal 144 and provides a corresponding sound signal output 154. In the present embodiment, the first speaker 150 is arranged immediately adjacent to the region 114 provided for the ear. Further, the first speaker 150 is oriented towards the region 114. In the present case, the correction microphone 110 and the first loudspeaker 150 are remote from one another, i.e. arranged in different edge regions of the region 114 provided for that ear. This avoids: the correction microphone 110 records only the sound signal output 154 of the first loudspeaker 150 as sound signals and forwards these sound signals as the correction signal 118. This enables: in addition to the sound signal output 154, the correction microphone 110 also records the ambient noise 124 as a sound signal and forwards these ambient noises as the correction signal 118. In another alternative embodiment, the correction microphone 110 and the first speaker 150 are arranged adjacent to each other.

In this embodiment, the active noise reduction (used as active noise suppression in the present case) that can be achieved by ANC unit 140 is achieved by: ANC unit 140 is configured to determine audio signal 144 based on classified signal 134 such that sound signal output 154 corresponding to audio signal 144 destructively interferes with at least a portion of ambient noise 124. Here, the portion of the acoustic signal output 154 of the ambient noise 124 that cancels and differentially interferes therewith corresponds to signal components from at least one class of the reference signal 128.

The apparatus 100 of the illustrated embodiment is configured such that the classification unit 130 and the ANC unit 140 are configured as separate electronic components from each other. In an alternative, not shown embodiment aspect according to the invention, the classifying unit and the ANC unit are configured as part of the sole signal processing unit of the device.

Fig. 2 shows a schematic configuration of an apparatus 200 according to a second embodiment of the first aspect of the present invention.

The device 200 differs from the device 100 shown in fig. 1 by the features described below.

The ANC unit 240 of the apparatus 200 is further configured to: receives reference signal 128 and correction signal 218 and processes reference signal 128 and correction signal 218 based on classified signal 234. In this way, particularly large amounts of signal information, in particular with regard to the ambient noise 124, can advantageously be taken into account during the processing by the ANC unit 240. In this embodiment, the classified signal 234 is a signal synchronized in time with the reference signal 128 in real time, which signal indicates the class of signal component currently assigned to the reference signal 128. In this way, the classified signal 234 is a pure control quantity for ANC unit 240 in this embodiment.

Unlike the correction signal 118 in fig. 1, the correction signal 218 is formed by processing by means of the correction microphone 110 and the subsequent band correction caused by the filter unit 260. Thus, the correction signal 218 is a processed correction signal.

Furthermore, the device 200 additionally comprises a signal booster 265 configured to: causing the provided audio signal 244 to be enhanced before it is received by the first speaker 150.

In a not shown embodiment, an alternative or additional signal enhancer is provided for enhancing the reference signal and/or the correction signal.

In a further embodiment, which is not shown, the filter unit is configured to: acting as a high pass filter and/or acting as a low pass filter. In this way, spectral components that are not important for the sound output can already be filtered out before unnecessary further processing.

The classification unit 230 of the apparatus 200 is further configured to: the reference signal 128 is output with more than two categories of signal components. Here, the classification unit 230 is configured to: consider the following categories of signal and/or noise groups: siren signals, vehicle noise, voice signals, pump noise, ventilation noise, fire noise. In other embodiments, the categories include at least one of the illustrated sets of signals and/or noise. Based on the classification thus performed by the classification unit 230, the ANC unit 240 is configured to provide the audio signal 244 such that the sound signal output 154 by the first loudspeaker 150 interferes with the sound signal in the area provided for that ear such that ambient noise of the respective predefined signal and/or noise group is perceived at a respective predefined amplitude in the area provided for that ear of the wearer of the device 200. In the present case, this achieves: speech at a volume that enables communication with surrounding people can be perceived. Furthermore, typical interference noise, such as pump noise, ventilation noise and fire noise, is suppressed to a large extent, while the siren signal and vehicle noise are kept at a moderate volume in order to keep the noise load of the wearer of the device 200 within a range that is not harmful to health.

Fig. 3 shows a schematic configuration of an apparatus 300 according to a third embodiment of the first aspect of the present invention.

The device 300 according to the invention differs from the

devices

100 and 200 in the features described below.

In addition to reference microphone 320, device 300 includes two

additional reference microphones

322, 324. The three reference microphones are oriented in three different directions relative to the wearer of the device 300. These reference microphones are also configured to: ambient noise in the ambient environment from the wearer of the device is recorded and forwarded. In this case, reference microphone 320 forwards reference signal 328, and

additional reference microphones

322, 324 forwards respective additional reference signals 329', 329 ". In this case, the classification unit 330 according to the present invention is configured to: the classified signal 334 is output based on the reference signal 328 and the two additional reference signals 329', 329 ".

The device 300 also includes a second speaker 370 and an additional correction microphone 380. The second speaker 370 is configured to: receives additional audio signals 346 output by ANC unit 340 and provides corresponding additional sound signal outputs 374. In an embodiment not shown, the additional audio signal corresponds to the audio signal. An additional correction microphone 380 is disposed proximate to region 314 provided for the other ear of the wearer of device 300 and is configured to: the sound signals in the region 314 provided for the other ear are recorded and forwarded as an additional correction signal 384.

In this case, the ANC unit 340 is configured to: an additional correction signal 384 is received and the correction signal 118 and the additional correction signal 384 are processed based on the classified signal 334. As a result of this processing, the audio signal 144 and the additional audio signal 346 are output. The audio signal 144 and the additional audio signal 346 are designed such that the active noise reduction in the respective region 114, 314 provided for the ear of the wearer of the device 300 depends on the position of the respective region relative to the noise direction of the signal or noise belonging to the suppressed category. The noise direction is determined by the known orientation of the three

reference microphones

320, 322, 324. In an embodiment not shown, the same audio signal is passed to the correction microphone and the additional correction microphone.

Fig. 4 shows a perspective view of a system 400 according to a first embodiment of the second aspect of the present invention.

The system 400 according to the invention comprises the device 100 shown in fig. 1, the only difference being that: the classification unit and the ANC unit are implemented in a common signal processing unit 410. The working principle of all components is as described in the context of fig. 1.

The system 400 according to the invention further comprises a helmet 420, wherein the first loudspeaker 150 is arranged to cause an output of a sound signal in a region of the ear of a wearer provided for the helmet 420. Furthermore, the correction microphone 110 is arranged immediately adjacent to the region provided for the ear. In this case, the correction microphone 110 is fixed to the first speaker 150 by the microphone holder 425, whereby a predetermined relative position of the correction microphone 110 and the first speaker 150 can be maintained even in the case where the system 400 is moved or under the action of a body load.

In the illustrated embodiment, the correction microphone 110 and the first speaker 150 are disposed in the fabric of the strap 430 of the helmet 420.

The reference microphone 120 is arranged outside the helmet 420. Here, the reference microphone is oriented in a direction away from the wearer of the system 400. In this way, it is advantageously ensured that: the ambient noise 124 recorded by the reference microphone 120 is not formed to a large extent by the sound signal output of the first loudspeaker 150.

To ensure noise protection, the wearer of the system 400 would wear a known passive hearing protection device in the ear that is not at the correction microphone 110.

In an embodiment, not shown, the first speaker of the system is not arranged in the immediate vicinity of the area provided for the ear, but in another area of the helmet, wherein the sound signal output is conducted via the resonance space to the wearer of the system, in particular to at least one ear of the wearer of the system.

Fig. 5 shows a perspective view of a system 500 according to a second embodiment of the second aspect of the present invention.

Unlike the system 400 shown in fig. 4, the system 500 includes the device 300 shown in fig. 3.

In this case, the classification unit and the ANC unit are arranged in a not shown housing in the inner region of the helmet behind from the wearer's point of view.

The

reference microphones

320, 322, 324 are arranged at different positions on the outside of the helmet 420 such that they are oriented in different directions. In this way, ambient noise from different directions can be recorded particularly well.

In a not shown embodiment of the system according to the invention, the plurality of reference microphones are arranged on a helmet strap, which can be arranged at the lower rim of a helmet, in particular a half-shell helmet. In this way, the system according to the invention can advantageously be arranged particularly simply on existing helmets.

Fig. 6 shows a perspective view of a system 600 according to a third embodiment of the second aspect of the present invention.

The system 600 according to the invention has: the device 300 shown in fig. 3; and a respirator 610, wherein the first speaker 150 and the second speaker 370 are arranged on the mask body 615 or the strap 618 of the respirator 610 such that the sound signal output and the additional sound signal output are made in regions provided for the ears of a wearer of the respirator, respectively. The correction microphone 110 and the additional correction microphone 380 are each arranged next to this region. In this case, the correction microphone 110 and the additional correction microphone 380 are arranged on the respective housings of the first and

second speakers

150, 370 taking into account the directional characteristics of these

microphones

110, 380. In the illustrated embodiment, the two

microphones

110, 380 are advantageously omni-directional microphones. In embodiments not shown, microphones with other directional characteristics are used.

The three

reference microphones

320, 322, 324 are integrated in a connection 620 of the respirator 610, which is used for connecting a gas filter or a respirator.

Within the respirator, the device according to the invention can be integrated particularly advantageously into existing electronics of known communication systems for respirators.

Fig. 7 shows a perspective view of a system 700 according to a fourth embodiment of the second aspect of the present invention.

Like the system 600 already shown in fig. 6, the system 700 according to the invention comprises a gas mask 710. The device according to the invention integrated therein comprises two

reference microphones

720, 724 which are arranged facing different directions on the outside of the respirator 720. The correction microphone 720 and the additional correction microphone 734 are integrated together with the first and

second speakers

740, 744 in respective

separate ear pieces

750, 754, which are each fastened to the respirator 710. Here, correction microphone 730 and additional correction microphone 734 are oriented towards the

respective loudspeaker

740, 744.

By means of the movable,

separate ear parts

750, 754, the system 700 according to the invention makes it possible to achieve particularly advantageous individual adaptation of the positions of the correction microphone and of the loudspeaker to the current individual head form of the wearer of the respirator.

Fig. 8 shows a block diagram of a method 800 according to an embodiment of the third aspect of the invention.

The method 800 for noise-dependent audio signal processing according to the invention has the following steps in chronological order.

The first step 810 includes: the sound signal in the region of the ear of the user provided for the method is recorded and the corresponding correction signal is forwarded.

The next step 820 includes: the ambient noise of the user of the method is recorded and the corresponding reference signal is forwarded.

The next step 830 includes: the method includes receiving the reference signal, dividing the reference signal into at least one first class and a second class of signal components according to a frequency spectrum of the reference signal and an amplitude of the reference signal and outputting corresponding classified signals.

The next step 840 includes: a correction signal is received, processed by a provided ANC unit based on the classified signal and a corresponding audio signal is output.

The final step 850 includes: receiving an audio signal and providing a corresponding sound signal output.

The method 800 according to the invention is repeated in a rapid time sequence, wherein the steps can be performed simultaneously or almost simultaneously. Thus, the active noise reduction by the provided ANC unit is based on: the sound signal output is continuously adapted to the current ambient noise in order to ensure a desired, partially cancelling interference between the sound signal output and the current ambient noise.

List of reference numerals

100. 200, 300 device according to the invention

110. 730 correction microphone

114. 314 are provided for the region of the wearer's ears

118 correction signal

120. 320, 720 reference microphone

124 ambient noise

128. 328 reference signal

130. 230, 330 classification unit

134. 234 classified signals

140. 240, 340 ANC unit

144. 244 audio signal

150. 740 first loudspeaker

154 sound signal output

218 enhanced correction signal

260 filter unit

265 signal enhancer

322. 324, 724 additional reference microphones

329', 329' additional reference signals

346 additional audio signal

370. 744 second loudspeaker

374 additional sound signal output

380. 734 additional correction microphone

384 additional correction signals

400. 500, 600, 700 system according to the invention

410 common signal processing unit

420 helmet

425 microphone holder

430 bundling belt of helmet

610. 710 gas mask

615 mask body

Binding band of 618 gas mask

620 connecting part

750 first ear piece

754 second ear piece

800 method according to the invention

810. 820, 830, 840, 850 method steps

Claims

1. A device (100) for noise dependent audio signal processing, the device having:

-a correction microphone (110) arranged in close proximity to a region (114) provided for an ear of a wearer of the device, and configured to: recording a sound signal in a region (114) provided for the ear and forwarding the sound signal as a correction signal (118);

-a reference microphone (120) arranged and constructed to: recording ambient noise (124) in the ambient environment from a wearer of the device (100) and forwarding the ambient noise as a reference signal (128);

-a classification unit (130) configured to: receiving the reference signal (128) and dividing the reference signal (128) into at least one first and second class of signal components according to the reference signal's frequency spectrum and the reference signal's amplitude and outputting a classified signal (134);

-an active noise reduction (ANC) unit (140) configured to: receiving the correction signal (118), processing the correction signal (118) based on the classified signal (134) and outputting a corresponding audio signal (114);

-a first speaker (150) configured to: receiving the audio signal (144) and providing a corresponding sound signal output (154),

wherein the classification unit (130) is configured to: outputting the reference signal (128) with more than two classes of signal components, and

wherein the category comprises at least one of the following groups of signals and/or noise: siren signals, vehicle noise, voice signals, pump noise, ventilation noise, fire noise.

2. The device (100) according to claim 1, wherein the device (100) further has a signal enhancer (265) configured to enhance the correction signal (118), the reference signal (128) and/or the audio signal (144).

3. The apparatus (100) according to at least any one of the preceding claims, wherein the ANC unit (140) is configured to: determining the audio signal (144) based on the classified signal (134) such that a sound signal output (154) based on the audio signal (144) is adapted for cancelling interference with a portion of the ambient noise corresponding to signal components from at least one class of the reference signal (128).

4. The apparatus (100) according to at least any one of the preceding claims, wherein the ANC unit (140) is configured to: assigning corresponding signal and/or noise groups to classes of the classified signals (134); and processing the correction signal (118) based on signal components of the classified signal (134) assigned to at least one predefined signal and/or noise group such that a sound signal output (154) based on the audio signal (144) is adapted to interfere with a portion of the ambient noise (124) such that the ambient noise (124) of the at least one predefined signal and/or noise group is perceptible at a predefined amplitude in a region (144) of the ear provided for a wearer of the device, the portion corresponding to the signal components of the reference signal (128) from the at least one predefined signal and/or noise group.

5. The device (300) of at least one of the preceding claims, wherein the device (300) further has a second speaker (370) and an additional correction microphone (380),

wherein the second speaker (370) is configured to: receiving the audio signal (144) or an additional audio signal (346) output by the ANC unit (340) and providing a corresponding additional sound signal output (374),

wherein the additional correction microphone (380) is arranged in close proximity to a region (314) provided for the other ear of the wearer of the device (300) and is configured to: recording a sound signal in a region (314) arranged for the other ear and forwarding the sound signal as an additional correction signal (384),

and wherein the ANC unit (340) is further configured to: the additional correction signal (384) is received, and the correction signal (118) and the additional correction signal (384) are processed based on the classified signal (134).

6. The device (300) of at least any one of the preceding claims, wherein the device (300) has at least one additional reference microphone (322) arranged and constructed to: -recording ambient environmental noise (124) in the ambient environment from the wearer of the device (300) and forwarding the ambient environmental noise as an additional reference signal (329'),

and wherein the classification unit (330) is configured to: outputting the classified signal (134) based on the reference signal (328) and the additional reference signal (329').

7. The device (100) according to at least one of the preceding claims, wherein the device (100) further has a microphone holder (425) which fixedly connects the correction microphone (110) and the first loudspeaker (150) to one another such that the relative position of the correction microphone (110) and the first loudspeaker (150) to one another cannot be changed.

8. A system (400) for noise-dependent audio signal processing, the system having:

-a device (100) according to at least any one of the preceding claims;

-a gas mask (610) and/or a helmet (420), wherein the first speaker (150) is arranged such that the sound signal output (154) is made in an area (114) provided for an ear of a wearer of the gas mask (610) and/or the helmet (420), and wherein the correction microphone (110) is arranged in close proximity to the area (114) provided for the ear.

9. The system (400) according to claim 8, wherein the reference microphone (120) is arranged at an outer surface of the gas mask (610) or the helmet (420) facing away from a wearer of the gas mask (610) and/or the helmet (420).

10. A method (800) for noise-correlated audio signal processing, the method having the steps (810, 820, 830, 840, 850) of:

-recording sound signals in a region (114) of an ear of a user arranged for the method and forwarding a corresponding correction signal (118);

-recording ambient noise (124) of a user of the method and forwarding a corresponding reference signal (128);

-receiving the reference signal (128), dividing the reference signal (128) into at least one first and second class of signal components according to its frequency spectrum and its amplitude and outputting a corresponding classified signal (134);

-receive the correction signal (118), process the correction signal (118) based on the classified signal (134) by means of a provided ANC unit (140) and output a corresponding audio signal (144); and also

-receive the audio signal (144) and provide a corresponding sound signal output (154).

11. The method (800) of claim 10, further having the step of:

-enhancing the correction signal (118), the reference signal (128) and/or the audio signal (144).

12. The method (800) of claim 10 or 11, further having the step of:

-assigning predefined signal and/or noise groups to corresponding classes of the classified signals (134); and processing, by the ANC unit (140), the correction signal (118) based on the signal components of the classified signal (134) assigned to at least one predefined signal and/or noise group such that a sound signal output (154) based on the audio signal (144) is adapted to interfere with a portion of the ambient noise (124) such that the ambient noise (124) of the at least one predefined signal and/or noise group is perceptible with a predefined amplitude in a region (114) of the ear provided for a user of the method, which portion corresponds to the signal components of the reference signal (128) from the at least one predefined signal and/or noise group.

13. The method (800) according to at least any one of claims 10 to 12, further having the step of:

-recording further sound signals in a region (314) of the other ear of the user arranged for the method and forwarding corresponding additional correction signals (380);

-receive the additional correction signal (380) and process the correction signal (118) and the additional correction signal (380) based on the classified signal (134);

-receiving the audio signal (144) and providing an additional sound signal output (374) in a region (314) of the other ear of a user arranged for the method.

14. The method (800) according to at least any one of claims 10 to 13, further having the step of:

-recording other ambient noise (124) of a user of the method and forwarding a corresponding additional reference signal (329');

-output the classified signal (134) based on the reference signal (128) and the additional reference signal (329').